I have one in a -68 dart with 4 spd.
Only been to the track 3 times with a clutch thats really holding me back and some other issues. Best so far is 9.87 with a lowsy 1.49 60 but at 143 mph. Car is 3000lbs.
New clutch is in the works and also worked the carb that had a clogged air bleed and no jet extensions😖
I think they are great engines that doesnt need alot of maintenance or work at all.
Very little torque so gear and light weight is key.
Im very happy with mine.